<template>
    <div>
        <!-- 面包屑导航区 -->
        <el-breadcrumb separator-class="el-icon-arrow-right">
            <el-breadcrumb-item :to="{ path: '/home' }">首页</el-breadcrumb-item>
            <el-breadcrumb-item>商品管理</el-breadcrumb-item>
            <el-breadcrumb-item>商品分类</el-breadcrumb-item>
        </el-breadcrumb>

        <!-- 卡片区域 -->
        <el-card>
            <el-row>
                <el-col>
                    <el-button type="primary" @click="showAddCateDialog">添加分类</el-button>
                </el-col>
            </el-row>
            <el-row>
                <!-- 表格区 -->
                <tree-table
                    :data="cateList"
                    :columns="columns"
                    :selection-type="false"
                    :expand-type="false"
                    :show-index="true"
                    index-text="#"
                    border
                    class="tree-table"
                >
                    <template v-slot:isok="scope">
                        <i
                            class="el-icon-success"
                            v-if="scope.row.cat_deleted === false"
                            style="color:lightgreen"
                        ></i>
                        <i class="el-icon-error" v-else style="color:red"></i>
                    </template>
                    <!-- 排序 -->
                    <template v-slot:order="scope">
                        <el-tag type="primary" size="mini" v-if="scope.row.cat_level===0">一级</el-tag>
                        <el-tag type="success" size="mini" v-else-if="scope.row.cat_level===1">二级</el-tag>
                        <el-tag type="warning" size="mini" v-else>三级</el-tag>
                    </template>
                    <!-- 操作 -->
                    <template v-slot:opt="scope">
                        <el-button type="primary" icon="el-icon-edit" size="mini">编辑</el-button>
                        <el-button type="danger" icon="el-icon-delete" size="mini">删除</el-button>
                    </template>
                </tree-table>
                <!-- 分页区 -->
                <el-pagination
                    @size-change="handleSizeChange"
                    @current-change="handleCurrentChange"
                    :current-page="queryInfo.pagenum"
                    :page-sizes="[3, 5, 10, 15]"
                    :page-size="queryInfo.pagesize"
                    layout="total, sizes, prev, pager, next, jumper"
                    :total="total"
                ></el-pagination>
            </el-row>
        </el-card>

        <!-- 添加分类的对话框 -->
        <el-dialog
            title="添加分类"
            :visible.sync="addCateDialogVisible"
            width="30%"
            @close="addCateDialogClosed"
        >
            <!-- 添加分类表单 -->
            <el-form
                :model="addCateForm"
                :rules="addCateFormRules"
                ref="addCateFormRef"
                label-width="100px"
            >
                <el-form-item label="分类名称：" prop="cat_name">
                    <el-input v-model="addCateForm.cat_name"></el-input>
                </el-form-item>
                <el-form-item label="父级分类：" prop="cat_name">
                    <!-- props用来指定配置对象 -->
                    <el-cascader
                        expand-trigger="hover"
                        v-model="selectedKeys"
                        :options="parentCateList"
                        :props="cascaderProps"
                        @change="parentCateChanged"
                        clearable
                        change-on-select
                    ></el-cascader>
                </el-form-item>
            </el-form>
            <span slot="footer" class="dialog-footer">
                <el-button @click="addCateDialogVisible = false">取 消</el-button>
                <el-button type="primary" @click="addCate">确 定</el-button>
            </span>
        </el-dialog>
    </div>
</template>

<script>
export default {
    data() {
        return {
            //查询数据的条件
            queryInfo: {
                type: 3,
                pagenum: 1,
                pagesize: 5
            },
            //商品分类的数据列表，默认为空
            cateList: [],
            //总数据条数
            total: 0,
            //为table指定列的定义
            columns: [
                {
                    label: "分类名称",
                    prop: "cat_name"
                },
                {
                    label: "是否有效",
                    //表示当前列定义为模板列
                    type: "template",
                    //表示当前这一列使用模板名称
                    template: "isok"
                },
                {
                    label: "排序",
                    //表示当前列定义为模板列
                    type: "template",
                    //表示当前这一列使用模板名称
                    template: "order"
                },
                {
                    label: "排序",
                    //表示当前列定义为模板列
                    type: "template",
                    //表示当前这一列使用模板名称
                    template: "opt"
                }
            ],
            /* 添加分类对话框的显示与隐藏 */
            addCateDialogVisible: false,
            //添加分类的表单数据对象
            addCateForm: {
                //将要添加的分类的名称
                cat_name: "",
                //父级分类的id
                cat_pid: 0,
                //分类的等级,默认为一级分类
                cat_level: 0
            },
            //添加分类表单的验证规则
            addCateFormRules: {
                cat_name: [
                    {
                        required: true,
                        message: "请输入分类名称",
                        trigger: "blur"
                    }
                ]
            },
            //父级分类的列表
            parentCateList: [],
            //指定级联配置对象
            cascaderProps: {
                value: "cat_id",
                label: "cat_name",
                children: "children"
            },
            //选中的父级分类的id数组
            selectedKeys: []
        };
    },
    created() {
        this.getCateList();
    },
    methods: {
        async getCateList() {
            const { data: res } = await this.$http.get("categories", {
                params: this.queryInfo
            });
            if (res.meta.status !== 200) {
                return this.$message.error("获取商品分类数据失败");
            }

            this.cateList = res.data.result;
            this.total = res.data.total;
        },
        //监听pagesize改变事件
        handleSizeChange(newSize) {
            this.queryInfo.pagesize = newSize;
            this.getCateList();
        },
        //监听pagenum的改变
        handleCurrentChange(newPage) {
            this.queryInfo.pagenum = newPage;
            this.getCateList();
        },
        //点击按钮显示添加分类对话框
        showAddCateDialog() {
            this.getParentCateList();
            this.addCateDialogVisible = true;
        },
        //获取父级分类的数据列表
        async getParentCateList() {
            const { data: res } = await this.$http.get("categories", {
                params: { type: 2 }
            });
            if (res.meta.status !== 200) {
                return this.$message.error("获取父级分类数据失败");
            }
            this.parentCateList = res.data;
        },
        //选中项发生变化触发
        parentCateChanged() {
            //如果selectedKeys数组中的length大于零，证明选中了父级分类
            //反之证明没有选中
            if (this.selectedKeys.length > 0) {
                //父级分类的id
                this.addCateForm.cat_pid = this.selectedKeys[
                    this.selectedKeys.length - 1
                ];
                //为当前分类等级赋值
                this.addCateForm.cat_level = this.selectedKeys.length;
                return;
            } else {
                //父级分类的id
                this.addCateForm.cat_pid = 0;
                //为当前分类等级赋值
                this.addCateForm.cat_level = 0;
            }
        },
        //添加分类
        addCate() {
            this.$refs.addCateFormRef.validate(async valid => {
                if (!valid) return;
                const { data: res } = await this.$http.post(
                    "categories",
                    this.addCateForm
                );
                if (res.meta.status !== 201) {
                    return this.$message.error("添加分类失败");
                }
                this.$message.success("添加分类成功");
                this.getCateList();
                this.addCateDialogVisible = false;
            });
        },
        //监听添加分类对话框的关闭事件，重置表单数据
        addCateDialogClosed() {
            this.$refs.addCateFormRef.resetFields();
            this.selectedKeys = [];
            this.addCateForm.cat_level = 0;
            this.addCateForm.cat_pid = 0;
        }
    }
};
</script>

<style lang="less" scoped>
.tree-table {
    margin-top: 15px;
}
.el-cascader {
    width: 100%;
}
</style>